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SIKA of ANSTO, inelastic neutron scattering, phonon dispersion, thermoelectric materials
SIKA Research on High-Performance Thermoelectric Materials Selected as a Cover Image of Advanced Science
2020/12/24
Dr. Yang-Yuan Chen’s research on thermoelectric materials using SIKA was selected as the cover image of Advanced Science.
An international research team, coordinated by Dr. Yang-Yuan Chen (Institute of Physics, Academia Sinica), conducted inelastic neutron scattering (INS) experiments using NSRRC’s SIKA, a cold neutron triple-axis spectrometer located at ANSTO (Australia’s Nuclear Science and Technology Organisation) Australia, and found the high-performance thermoelectric properties of the GeTe-based materials by their synthesis. The research results were published in the international journal Advanced Science and were chosen to decorate the inside back cover of the November-December 2020 issue. 
 
The team systematically investigated the effects of Sb doping on GeTe crystals, and enhanced the thermoelectric figure-of-merit zT of Ge0.92Sb0.08Te single crystal to "2.2". The higher the zT value of a material, the better its thermoelectric properties. According to the observed defect structures in nanoscales, neutron scattering experiments, density functional theory calculations, and Raman spectroscopy measurements, some abnormal phonon scattering mechanisms have been discovered. This research provides a new perspective to explore emerging high zT thermoelectric materials for green energy applications.
 
The team used SIKA to perform INS experiments and obtained good quality phonon-dispersion data for both GeTe and Ge0.92Sb0.08Te samples. The research results highlight the importance of phonon engineering approaches to improving thermoelectric performance.